1. Field of the Invention
This invention relates to the transporting of heavy fuel oil in a transportation system, e.g., a pipeline. The heavy fuel oil is congealed into particles, the particles are coated with a high pour point fraction of the heavy fuel in question and the coated particles are slurried with water for transporting in a pipeline.
2. Prior Art
Pumping of heavy fuel oils at temperatures below the pour point thereof is very difficult. These fuels are very viscous and cannot by pumped at usual pipeline temperatures. Heating pipelines to adequately reduce viscosity is uneconomical and the use of pour point depressors and viscosity breaking agents have been tried with little success. In addition, heavy residual fuels have been congealed, suspended in water, and the combination pumped at temperatures below the pour point of the heavy residual fuel.
Examples of patents representative of the art include:
Merrill, et al., in U.S. Pat. No. 3,804,752, teaches the transportation of waxy crude oils by separating the mixture into high and low pour point fractions, congealing the high pour point fraction and thereafter slurrying the congealed particles in the low pour point fraction at a temperature below the congealation temperature of the high pour point fraction.
Fonseca, et al., in U.S. Pat. No. 3,767,738, coats prilled sulfur pellets with a polyhydroxy compound to inhibit degradation during pipelining in a fluid carrier.
Bonteil, in U.S. Pat. No. 3,670,520, atomizes a liquid or a semi-liquid product into droplets and passes those droplets down through a rising current of cold gas which superficially freezes the droplets whereupon the droplets fall in a fluidized bed where the freezing process is completed.
Sachsel, et al., in U.S. Pat. No. 3,202,533, freezes compounds which are liquid at room temperature into frozen core particles and incapsulates the particles with materials insoluble in a storage solvent at room temperature.
Nack, in U.S. Pat. No. 3,036,338, creates substantially spherical pellets of fusible materials and coats the pellets to prevent agglomeration.
Moar, in U.S. Pat. No. 3,026,568, forms bitumen pellets or granules by spraying them downwardly into an upwardly direct stream of air carrying a powder which coates the pellets or granules preventing adherence and agglomeration.
Watanabe, in U.S. Pat. No. 3,468,986, forms spherical particles of a wax/polymer blend by disbursing the melted blend in a non-solvent liquid (e.g., water) and thereafter cooling the disbursed wax/polymer blend to form discrete solid particles which can be coated with finely divided coating solids such as calcium carbonate, etc.
Merrell, in U.S. Pat. No. 3,853,356, fractionates a crude oil into a relatively high pour point fraction, a relatively medium pour point fraction, and a relatively low pour point fraction; the medium pour point fraction being congealed and slurried in a mixture of the relatively low pour point fraction and a portion of the high pour point fraction.
This technology has generally proven to be economically unattractive and technically ineffective for heavy fuel oils which have a tendency to dissolve and agglomerate in a carrier liquid.